diff --git a/src/clientP2P/ClientP2P.java b/src/clientP2P/ClientP2P.java
index f7a236b..3ce9879 100644
--- a/src/clientP2P/ClientP2P.java
+++ b/src/clientP2P/ClientP2P.java
@@ -89,28 +89,28 @@ public class ClientP2P {
 		final ServerPortRange serverPortRange = new ServerPortRange();
 		final TrackerPortRange trackerPortRange = new TrackerPortRange();
 
-		if ((args.length != 6) && (args.length != 0)){
+		if ((args.length != 6) && (args.length != 0)) {
 			ClientP2P.printUsage(serverPortRange, trackerPortRange);
 			System.exit(1);
 		}
-		else if(args.length == 6){
+		else if (args.length == 6) {
 				protocolClient = args[1];
 				hostnameServer = args[2];
 				portServer = Integer.valueOf(Integer.parseInt(args[3]));
 				hostnameTracker = args[4];
 				portTracker = Integer.valueOf(Integer.parseInt(args[5]));
-		} else{
+		} else {
 			System.out.println("Client, wich transport protocol do you want to use (default = TCP): ");
 			protocolClient = scanner.nextLine();
 			System.out.println("server side, enter hostname to bind (default = localhost): ");
 			hostnameServer = scanner.nextLine();
-			if(hostnameServer.equals("")){
+			if (hostnameServer.equals("")) {
 				hostnameServer = defaultHostname;
 				System.out.println("using default hostname : " + hostnameServer);
 			}
 			System.out.println("enter port (default = " + serverPortRange.getDefaultPort() +"): ");
 			String portServerStr = scanner.nextLine();
-			if(portServerStr.equals("")){
+			if (portServerStr.equals("")) {
 				portServer = serverPortRange.getDefaultPort();
 				System.out.println("using default port : " + portServer);
 			} else {
@@ -118,13 +118,13 @@ public class ClientP2P {
 			}
 			System.out.println("enter hostname of tracker (default = localhost): ");
 			hostnameTracker = scanner.nextLine();
-			if(hostnameTracker.equals("")){
+			if (hostnameTracker.equals("")) {
 				hostnameTracker = defaultHostname;
 				System.out.println("tracker default hostname : " + hostnameTracker);
 			}
 			System.out.println("enter tracker's port (default = "+trackerPortRange.getDefaultPort() + "): ");
 			String portTrackerStr = scanner.nextLine();
-			if(portTrackerStr.equals("")){
+			if (portTrackerStr.equals("")) {
 				portTracker = trackerPortRange.getDefaultPort();
 				System.out.println("using default port : " + portTracker);
 			} else {
@@ -132,63 +132,66 @@ public class ClientP2P {
 			}
 		}
 
-		if (serverPortRange.isPortInRange(portServer)){
-			if(trackerPortRange.isPortInRange(portTracker)){
-				System.out.println("using hostname : " + hostnameServer);
-				System.out.println("using port : " + portServer);
-				System.out.println("tracker hostname : " + hostnameTracker);
-				System.out.println("tracker port : " + portTracker);
-				ClientP2P c = new ClientP2P(hostnameServer, portServer, hostnameTracker, portTracker);
-				ServerManagementUDP smudp = new ServerManagementUDP(c.directories.getDataHomeDirectory(), c.server, c.tracker, c.loggerServer);
-				ServerManagementTCP smtcp = new ServerManagementTCP(c.directories.getDataHomeDirectory(), c.server, c.tracker, c.loggerServer);
-				Thread tudp = new Thread(smudp);
-				tudp.setName("server UDP P2P-JAVA-PROJECT");
-				tudp.start();
-				Thread ttcp = new Thread(smtcp);
-				ttcp.setName("server TCP P2P-JAVA-PROJECT");
-				ttcp.start();
+		boolean serverInRange = serverPortRange.isPortInRange(portServer);
+		boolean trackerInRange = trackerPortRange.isPortInRange(portTracker);
 
-				// Wait a bit before printing client interface
-				// This is not required, but allow to have a cleaner interface
-				try {
-					Thread.sleep(200);
-				} catch(InterruptedException e) {
-					Thread.currentThread().interrupt();
-				}
+		if (serverInRange && trackerInRange) {
+			System.out.println("using hostname : " + hostnameServer);
+			System.out.println("using port : " + portServer);
+			System.out.println("tracker hostname : " + hostnameTracker);
+			System.out.println("tracker port : " + portTracker);
+			ClientP2P c = new ClientP2P(hostnameServer, portServer, hostnameTracker, portTracker);
+			ServerManagementUDP smudp = new ServerManagementUDP(c.directories.getDataHomeDirectory(), c.server, c.tracker, c.loggerServer);
+			ServerManagementTCP smtcp = new ServerManagementTCP(c.directories.getDataHomeDirectory(), c.server, c.tracker, c.loggerServer);
+			Thread tudp = new Thread(smudp);
+			tudp.setName("server UDP P2P-JAVA-PROJECT");
+			tudp.start();
+			Thread ttcp = new Thread(smtcp);
+			ttcp.setName("server TCP P2P-JAVA-PROJECT");
+			ttcp.start();
 
-				Thread tclient;
-				switch(protocolClient){
-					case "UDP":
-					case "udp":
-					case "upd": // to avoid users typos
-					case "2" :
-						System.out.println("Starting with UDP");
-						ClientManagementUDP cmudp = new ClientManagementUDP(c.directories.getDataHomeDirectory(), c.tracker, c.directories.getDataHomeDirectory() + c.partsDir, c.loggerClient, c.scanner, c.server);
-						tclient = new Thread(cmudp);
-						break;
-					case "TCP":
-					case "tcp":
-					case "1":
-					default:
-						System.out.println("Starting with TCP");
-						ClientManagementTCP cmtcp = new ClientManagementTCP(c.directories.getDataHomeDirectory(), c.tracker, c.directories.getDataHomeDirectory() + c.partsDir, c.loggerClient, c.scanner, c.server);
-						tclient = new Thread(cmtcp);
-						break;
-				}
-				tclient.setName("client P2P-JAVA-PROJECT");
-				tclient.start();
-				try {
-					tclient.join();
-				} catch (InterruptedException e) {}
-				smudp.setStop();
-				smtcp.setStop();
+			// Wait a bit before printing client interface
+			// This is not required, but allow to have a cleaner interface
+			try {
+				Thread.sleep(200);
+			} catch (InterruptedException e) {
+				Thread.currentThread().interrupt();
 			}
-			else{
-				System.out.println("\n TRACKER: Port not in range. " + trackerPortRange);
+
+			Thread tclient;
+			switch (protocolClient) {
+				case "UDP":
+				case "udp":
+				case "upd": // to avoid users typos
+				case "2" :
+					System.out.println("Starting with UDP");
+					ClientManagementUDP cmudp = new ClientManagementUDP(c.directories.getDataHomeDirectory(), c.tracker, c.directories.getDataHomeDirectory() + c.partsDir, c.loggerClient, c.scanner, c.server);
+					tclient = new Thread(cmudp);
+					break;
+				case "TCP":
+				case "tcp":
+				case "1":
+				default:
+					System.out.println("Starting with TCP");
+					ClientManagementTCP cmtcp = new ClientManagementTCP(c.directories.getDataHomeDirectory(), c.tracker, c.directories.getDataHomeDirectory() + c.partsDir, c.loggerClient, c.scanner, c.server);
+					tclient = new Thread(cmtcp);
+					break;
 			}
-		}
-		else{
-			System.out.println("\n SERVER: Port not in range. " + serverPortRange);
+			tclient.setName("client P2P-JAVA-PROJECT");
+			tclient.start();
+			try {
+				tclient.join();
+			} catch (InterruptedException e) {}
+			smudp.setStop();
+			smtcp.setStop();
+		} else {
+			if (!serverInRange) {
+				System.err.println("SERVER: Port not in range. " + serverPortRange);
+			}
+			if (!trackerInRange) {
+				System.err.println("TRACKER: Port not in range. " + trackerPortRange);
+			}
+			System.exit(2);
 		}
 	}
 }
diff --git a/src/serverP2P/ServerP2P.java b/src/serverP2P/ServerP2P.java
index 7835f62..90b7451 100644
--- a/src/serverP2P/ServerP2P.java
+++ b/src/serverP2P/ServerP2P.java
@@ -39,7 +39,7 @@ public class ServerP2P {
 		directories.createSubdir(subdir);
 		logger = new Logger(directories.getDataHomeDirectory() + "server.log");
 		System.out.println("Server will listen on port " + portServer + " and serve files from " + directories.getDataHomeDirectory() + subdir);
-		if(isInteractive){
+		if (isInteractive) {
 			directories.askOpenDataHomeDirectory(subdir, scanner);
 		}
 		scanner.close();
@@ -61,40 +61,43 @@ public class ServerP2P {
 			Scanner scanner = new Scanner(System.in);
 			boolean isInteractive = false;
 
-			if ((args.length != 5) && (args.length != 0)){
+			if ((args.length != 5) && (args.length != 0)) {
 				System.out.println("usage : java serveurP2P.ServeurP2P (interactive) or java serveurP2P.ServeurP2P -- <serveurHOSTNAME> <serveurPORT> <trackerHOSTNAME> <trackerPORT> (" + serverPortRange + " and " + trackerPortRange +")");
 				System.exit(1);
 			}
-			else if(args.length == 5){
-					hostnameServer = args[1];
-					portServer = Integer.valueOf(Integer.parseInt(args[2]));
-					hostnameTracker = args[3];
-					portTracker = Integer.valueOf(Integer.parseInt(args[4]));
+			else if (args.length == 5) {
+				isInteractive = false;
+				hostnameServer = args[1];
+				portServer = Integer.valueOf(Integer.parseInt(args[2]));
+				hostnameTracker = args[3];
+				portTracker = Integer.valueOf(Integer.parseInt(args[4]));
 			} else {
 				isInteractive = true;
+				// configure application
 				System.out.println("Server, enter hostname to bind (default = localhost): ");
 				hostnameServer = scanner.nextLine();
-				if(hostnameServer.equals("")){
+				if (hostnameServer.equals("")) {
 					hostnameServer = defaultHostname;
 					System.out.println("using default hostname : " + hostnameServer);
 				}
-				System.out.println("enter port (default = " + serverPortRange.getDefaultPort() + "): ");
+				System.out.println("Enter port (default = " + serverPortRange.getDefaultPort() + "): ");
 				String portServerStr = scanner.nextLine();
-				if(portServerStr.equals("")){
+				if (portServerStr.equals("")) {
 					portServer = serverPortRange.getDefaultPort();
 					System.out.println("using default port : " + portServer);
 				} else {
 					portServer = Integer.valueOf(Integer.parseInt(portServerStr));
 				}
-				System.out.println("enter hostname of tracker (default = localhost): ");
+				// configure tracker
+				System.out.println("Enter hostname of tracker (default = localhost): ");
 				hostnameTracker = scanner.nextLine();
-				if(hostnameTracker.equals("")){
+				if (hostnameTracker.equals("")) {
 					hostnameTracker = defaultHostname;
 					System.out.println("tracker default hostname : " + hostnameTracker);
 				}
-				System.out.println("enter tracker's port (default = " + trackerPortRange.getDefaultPort() + "): ");
+				System.out.println("Enter tracker's port (default = " + trackerPortRange.getDefaultPort() + "): ");
 				String portTrackerStr = scanner.nextLine();
-				if(portTrackerStr.equals("")){
+				if (portTrackerStr.equals("")) {
 					portTracker = trackerPortRange.getDefaultPort();
 					System.out.println("using default port : " + portTracker);
 				} else {
@@ -102,28 +105,30 @@ public class ServerP2P {
 				}
 			}
 
-			if (serverPortRange.isPortInRange(portServer)){
-				if(trackerPortRange.isPortInRange(portTracker)){
-					System.out.println("using hostname : " + hostnameServer);
-					System.out.println("using port : " + portServer);
-					System.out.println("tracker hostname : " + hostnameTracker);
-					System.out.println("tracker port : " + portTracker);
-					ServerP2P s = new ServerP2P(hostnameServer, portServer, hostnameTracker, portTracker, isInteractive);
-					ServerManagementUDP smudp = new ServerManagementUDP(s.directories.getDataHomeDirectory() + subdir, s.server, s.tracker, s.logger);
-					ServerManagementTCP smtcp = new ServerManagementTCP(s.directories.getDataHomeDirectory() + subdir, s.server, s.tracker, s.logger);
-					Thread tudp = new Thread(smudp);
-					tudp.setName("server UDP P2P-JAVA-PROJECT");
-					tudp.start();
-					Thread ttcp = new Thread(smtcp);
-					ttcp.setName("server TCP P2P-JAVA-PROJECT");
-					ttcp.start();
+			boolean serverInRange = serverPortRange.isPortInRange(portServer);
+			boolean trackerInRange = trackerPortRange.isPortInRange(portTracker);
+			if (serverInRange && trackerInRange) {
+				System.out.println("using hostname : " + hostnameServer);
+				System.out.println("using port : " + portServer);
+				System.out.println("tracker hostname : " + hostnameTracker);
+				System.out.println("tracker port : " + portTracker);
+				ServerP2P s = new ServerP2P(hostnameServer, portServer, hostnameTracker, portTracker, isInteractive);
+				ServerManagementUDP smudp = new ServerManagementUDP(s.directories.getDataHomeDirectory() + subdir, s.server, s.tracker, s.logger);
+				ServerManagementTCP smtcp = new ServerManagementTCP(s.directories.getDataHomeDirectory() + subdir, s.server, s.tracker, s.logger);
+				Thread tudp = new Thread(smudp);
+				tudp.setName("server UDP P2P-JAVA-PROJECT");
+				tudp.start();
+				Thread ttcp = new Thread(smtcp);
+				ttcp.setName("server TCP P2P-JAVA-PROJECT");
+				ttcp.start();
+			} else {
+				if (!serverInRange) {
+					System.err.println("SERVER: Port not in range. " + serverPortRange);
 				}
-				else{
-					System.out.println("\n TRACKER: Port not in range. " + trackerPortRange);
+				if (!trackerInRange) {
+					System.err.println("TRACKER: Port not in range. " + trackerPortRange);
 				}
-			}
-			else{
-				System.out.println("\n SERVER: Port not in range. " + serverPortRange);
+				System.exit(2);
 			}
 		}
 }
diff --git a/src/tracker/Tracker.java b/src/tracker/Tracker.java
index 9dec113..ba8ff4a 100644
--- a/src/tracker/Tracker.java
+++ b/src/tracker/Tracker.java
@@ -32,7 +32,7 @@ public class Tracker {
 		logger = new Logger(directories.getDataHomeDirectory() + "tracker.log");
 		System.out.println("Tracker will listen on port " + port + " and write logs into " + directories.getDataHomeDirectory());
 		Scanner scanner = new Scanner(System.in);
-		if(isInteractive){
+		if (isInteractive) {
 			directories.askOpenDataHomeDirectory(null, scanner);
 		}
 		scanner.close();
@@ -52,23 +52,24 @@ public class Tracker {
 		Tracker t;
 		boolean isInteractive = false;
 
-		if ((args.length != 3) && (args.length != 0)){
+		if ((args.length != 3) && (args.length != 0)) {
 			System.out.println("usage : java tracker.Tracker (interactive) or java trackerP2P.trackerP2P -- <hostname> <PORT> (" + trackerPortRange +")");
 			System.exit(1);
-		} else if (args.length == 3){
-				hostname = args[1];
-				port = Integer.valueOf(Integer.parseInt(args[2]));
+		} else if (args.length == 3) {
+			isInteractive = false;
+			hostname = args[1];
+			port = Integer.valueOf(Integer.parseInt(args[2]));
 		} else {
 			isInteractive = true;
 			System.out.println("Tracker Server, enter hostname to bind (default = localhost): ");
 			hostname = scanner.nextLine();
-			if(hostname.equals("")){
+			if (hostname.equals("")) {
 				hostname = defaultHostname;
 				System.out.println("using default hostname : " + hostname);
 			}
 			System.out.println("enter port (default = " + trackerPortRange.getDefaultPort() +"): ");
 			String portStr = scanner.nextLine();
-			if(portStr.equals("")){
+			if (portStr.equals("")) {
 				port = trackerPortRange.getDefaultPort();
 				System.out.println("using default port : " + port);
 			} else {
@@ -77,7 +78,7 @@ public class Tracker {
 		}
 
 		System.out.println("using hostname : " + hostname);
-		if(trackerPortRange.isPortInRange(port)) {
+		if (trackerPortRange.isPortInRange(port)) {
 			System.out.println("using port : " + port);
 			t = new Tracker(hostname, port, isInteractive);
 			TrackerManagementUDP tmudp = new TrackerManagementUDP(t.tracker, t.logger);
@@ -88,9 +89,9 @@ public class Tracker {
 			Thread ttcp = new Thread(tmtcp);
 			ttcp.setName("Tracker TCP P2P-JAVA-PROJECT");
 			ttcp.start();
-		}
-		else {
+		} else {
 			System.out.println("Port not in range. " + trackerPortRange);
+			System.exit(2);
 		}
 	}
 }